Hydraulic vehicle propulsion system



April 7, 1942. H. J. NATHAN HYDRAULIC VEHICLE PROPULSION SYSTEM Filed July 28, 1938 '7 Sheets-Sheet l Aii'orneys April 7, 1942. H. J. NATHAN 2,279,008

HYDRAULIC VEHICLE PROPULSION SYSTEM I Filed July 28, 1938 7 Sheets-Sheet 2 I" -5 W 5744 w/ 5 A Ziarraeys April 7, 1942. H. J. NATHYAN 2,279,008

HYDRAULIC VEHICLE PROPULSION SYSTEM Filed July 28, 1938 '7 Sheets-Sheet 5 April 7, 1942. H, NA HAN 4 2,279,008

HQDRAULIC VEHICLE PROPULSION SYSTEM Filed July 28, 1938 7 Sheets-Sheet 4 AZZOTWZZJS v 1942- H. J. NATHAN 2,279,008

HYDRAULIC VEHICLE PROPULSION SYSTEM Filed July 28, 1958 .7 Sheets-Sheet 6 April 7, 1942. H. J. NATHAN HYDRAULIC ViHICLE PROPULSION SYSTEM 7 Sheets-Sheet 7 ffi/ew/ior Filed July 28, 1938 A ZZorn/eys Patented Apr. 7, 1942 4 UNITED STATES PATENT OFFICE HYDRAULIC VEHICLE PROPULSION SYSTEM Herbert J. Nathan, Bismarck, N. nan.

Application July 28, 1938, Serial No. 221,815

(01. eo ss)' 2 Claims.

A more specific object is to provide a hydraulic system capable of performing or obviating the need of functions conventionally obtained by means of the usual clutch, transmission universal joint, drive shaft, differential, axle shafts, service brakes, parking brakes, free-wheeling device and a speedometer drive means of approximate accuracy.

Another object is to provide such a system enabling an improved type of knee-action wheelsuspension for all four wheels of a vehicle, and

wheel suspension apparatus suited for a vehicle having such a system incorporated therein.

Yet another object is to provide a system including speedometer drive means enabling approximate indication of rate of travel and recording of distance travelled not only in the forward-direction but also in the reverse direction.

Still another object is to'provide such a system having a common control element for forward, reverse and parking brake functions.

Anotherobject is to provide such a system having a single device providing for excess pressure release and also aifording a free-wheeling eilect;

A further object is to provide such a. system of 'simple, compact, light, rugged and inexpensive construction.

These and other objects of the invention will more fully appear from the following description wherein like reference characters refer to the same or similar parts throughout the views, and, in which:

Fig. 1 is a top view of a motor vehicle having Fig. 2 is a simplified diagrammatic representation of the system illustrated in Fig. 1;

Fig. 3 is a vertical sectional view of the reservoir and settling chamber of my system;

Fig. 4 is a sectional view of the speedometer an embodiment of my system incorporated theredrive motor of my system taken along the line 4-4 of Fig. 5 as indicated by the arrows;

Fig. 5 is'a sectional view of the speedometer drive motor taken along the line 5-5 of Fig. 4 as indicated by the arrows;

Fig. 6 is a sectional view of the reversing and parking brake valve of my system taken along the line 6'-6 of Fig. '7 as indicated by the arrows;

Fig. '7 is a sectional view of the valve of Fig. 6 taken along the line 1-1 of Fig. 6 as indicated by the arrows; I

Fig. 8 is a sectional view of the excess pressure relief and free-wheeling valve of my system;

Fig. 9 is a sectional view taken along the line 99 of Fig. 8 as indicated by the arrows;

Fig. 10 is a sectional view taken along the line Ill-I0 of Fig. 8 as indicated by the arrows;

Fig. 11 is a sectional view of the service brake valve of my system taken along the line H-H of Fig. 12 as indicated by the arrows;

- Fig. 12 is a sectional view taken along the line IZ-IZ of Fig. 11 as indicated by the arrows;

Fig. 13 is a sectional view taken along the line l3-l3 of Fig. 12 as indicated by the arrows;

Fig. 14 is a sectional view taken along the line I l-I l oi Fig.'12 as indicated by the arrows;

Fig. 15 is a view of one form of control apparatus fora portion of my system;

Fig. '16 is a detail sectional view of. one of the devices of Fig. 15;

Fig. 17 is a partially sectional view of control means for another portion of my system;

Fig. 18 is a partially sectional view of control -means for still another portion of my system;

Fig. 19 is a partially sectional view of control means corresponding to a portion of that of Fig. 15 but of a somewhat different form;

Fig. 20 is a longitudinal sectional view of a motor vehicle chassis having my wheel suspension incorporated therein; and

Fig. 21 is a partially broken away, partially sectional front view'of the chassis of Fig. 20.

Referring to the drawings Fig. 1 shows a motor vehicle chassis having incorporated therein a hydraulic propulsion and control system constituting an embodiment of my invention. The I .chassls illustrated includes a frame 25, tires 26,

tire rims 21, and an internal combustion engine 28, all of substantially conventional construction. The engine 28 is shown situated in the rear portion of thechassis but may be placed in the forward portion if desired. The engine 28 is, of course, supported from the frame byany means suitable for the purpose.

My propulsion and control system includes a' extending transversely of the. tank 39. The botreservoir A, a pump B, an automatic excess pressure relief and free-wheeling valve C, a reversing and parking brake valve D, four hydraulic wheel driving motors E associated with the respective tire rims 21, a service brake valve F, and an auxiliary fluid motor G for driving a speedometer. The fluid pump B may be of any variable capacity type which is controllable to vary the volume of fluid displaced by the same per revo-v lution thereof. Preferably the j fluid pump-B should be adjustable'in capacity throughout the entire range from full capacity down to zero capacity. The driving element of the pump'B is connected to the crank shaft of the engine 23.

The above mentioned devices included in my system will be described later in detail. The respective devices are connected together by-suitable conduits as shown in Fig. 1 and as indicated in the diagrammatic view of Fig. 2. An outlet of the reservoir A is connected by means of a pump inlet conduit 29 to the inlet of the pump B. The outlet of the pump B is connected by means of a pump outlet conduit 39 to one of the three ports of the automatic valve C Another port of the valve is connected through a bypass conduit 3| to the reservoir A. A third port of the valve C is connected to a port of the reversing valve D by-mounting the valve C ,on the valve D with the ports referred to in registration. Two ports of the reversing valve D are connected through wheel motor conduits 32 and 33 to the four wheel driving fluid motors E. Each of the wheel motors E has two individual conduits 34 and '35 respectively connected to the main motor conduits 32 and 33. Portions 34a and 35a of the conduits 34 and 35 extending from points on the frame 25 to the wheel motors E are formed of such material as to be flexible to permit movement of the wheel motor relative to the frame 25 for purposes of spring action and steering. The remaining port of the reversing valve D is connected through the-conduit 36 to the brake valve F. Another conduit 31 runs from the brake valve F to the speedometer drive motor G, and still another conduit 33 runs from the speedometer drive motor G to the reservoir A.

The reservoir A includes an open topped tank 39 having an outwardly projecting flange 39a extending around its upper edge and to which a top cover or closure plate 40 is secured by suitable means such as the bolts 40a. The cover plate 40 is provided with a flller cap 4| normally carried by a flller neck 42 as shown. Within the left-hand portion of the tank 39 a plate 43 is provided disposed in a horizontal plane spaced above the bottom of'the tank 39 a substantial distance. 'The left-hand end of the plate- 43 is provided with a vertically projecting ex- 60 tension 43a of the plate 43. The vertical portion 43a of the plate 43 is provided with an apertured boss 43b in registration with which the left-hand side of the tank .39 is apertured. A flanged centrally apertured plug 44 is externally screwthreaded and is screwed into internal. screwthreads formed in the boss 43b so as to secure the portion 43a of the plate 43 to the tank 39 for support therefrom. The plug 44 constitutes a fluid inlet connection element to which the conduit 33 is connected. The plate 43 is provided with upwardly projecting fins 430 on its upper side-and downwardly projecting flns 43d on its lower side, all of these fins being spaced from each other and disposed in vertical planes tom of the tank 39 is provided with upwardly projecting flns 45 arranged to project a slight distance into the spaces between adjoining ones of the fins 43d. The tank 39 is provided in the lower left-hand portion thereof with apertures 43 and 41 placed in communication with the respective pump inlet and bypass conduits 29 and 3|. It is to be noted that the aperture 46,

which is in communication with the inlet of the pump Bthrough the conduit 29,'is situated at a higher levelthan the aperture 41 which is connected to the bypass valve Q through the conduit 3! and through which fluid flow in the fluid. circulation path that is in effect during coasting and braking operations of the system. This relation between the levels at which the apertures 49 and 41 are respectively situated is such that, should the fluid level in the reservoir A become abnormally low, supply of fluid through the pump inlet conduit 29 for propulsion purposes will fail and prevent propulsion of the vehicle while a supply of fluid through the conduit 3| to the fluid circulation, circuit involved in braking operations is still available. This arrangement provides an automatic safety feature whereby, the propulsion function of the system will fall before the braking function is impaired in cases where the depth of fluid in the reservoir A recedes below normal due to leakage or any other cause. The fins 43c, 43d and 45 are for the purpose of facilitating the settling of particles of material from fluid entering the reservoir 39 through the inlet plug 44 and leaving the reservoir 39 through either of the conduits 29 or 3|. The fins 43d and 45 force the fluid to follow a zigzag path tending to improve the settling action. The spaces between the fins 43c and the spaces between the flns 45 constitute pockets for receiving particles which havesettled. In the right-hand portion of the tank 39 two spaced vertical partitions 48and 48b are disposed transversely of the tank 39, to provide therewithin a chamber 480 between the partitions 49 and 48b and another chamber 49d between the partition 48b and the right-hand end of the tank 39. An aperture 43a is formed in the upper portion of the partition 48b to provide for passage of air between the chambers 50 43c and 43d. An L-shaped tubular element 59 is attached to the left-hand side of the partition 43 with its lower portion extending through an apertured portion of the partition 43. The tube 39 is open at its ends. The right-hand one of the fins 45 on the bottom of the tank 391s in close proximity to but slightly spaced from the lowermost portion of the partition 43. The partitions 43 and 43b may be secured-to the cover plate 49 for support therefrom and at their vertical edges should fit tightly against the sides of the tank 39. Suitable means for indicating the level of the fluid in the tank 39 is provided and may consist of a float 49 connected through a rod 53 to a suitable'fluid level indicating device 5| situated on the upper surfaces of the top cover 49. A breather devicefor" admitting air the tank 391s provided. This device consists of a small casing 52 connected at its upper end through a small conduit 53 to the upper p rtion of the chamber 43d. The casing 52 includes a generally U- shaped tube 54 having one leg 54a thereof extending downwardly into the interior 1 of the casing 52 to a point slightly above the bottom ofthe casing 52.. The remaining leg into the tank 39 andpermitting exit of air from' 54b of the tube 54 projects downwardly exteriorly of the casing 52. The casing 52 is filled to a point somewhat below the upper limits thereof with liquid 55.

The speedometer drive fluid motor G is illustrated in Figs. 4 and 5 and includes a casing comprising two members 51 and 58 placed together to define an interior space 59 ofgenerally cylindrical shape. The respective halves 51 and 58 of the casing are provided with ears 51a and 580 which are apertured and which are held together by means of nutted bolts 60. The lower portions of the members 51 and 58 are extended and recessed to provide therewithin axially aligned respective inlet and outlet passages 61 and 62. Within the interior space 59 a rotor lation to each other as shown in Fig. 6. The v ports 15, 16. I1 and 18 are aligned with the space between the disks 12 and 13 so asto be in communication with said space. A vane 19 extendingdiametrically of the casing 1| from one side to the other thereof extends between the disks 12 and 13 and may be formed inte- $3 is provided. The rotor 53 is centered relagrally therewith. The ends of the vanes I9 are widened and are provided with outwardly facing recesses 19a therein suited for registration with ones of the ports l5, l8, l1 and 18 with which the ends of the vanes '89 may be aligned. At

having therein sealing elements 89 bearing against the interior periphery of the casing H and urged against said periphery by means of 4 fiat arched springs 9| situated in the grooves 58?) apertured to constitute a bearing wherein the shaft 63?) is journalled. The outer side of the boss 59b is recessed to receive a sealing ring 54 and internally screw-threaded to receive a centrally apertured externally screw-threaded plug 55 for retaining the sealing ring 64 in place.

The rotor 63 carries thereon an annular series of equally spaced radially projecting arms 65 on cups at the lower side of the rotor 63 face the.

inlet passage ti. A pair of arcuate elements 558 are carried or formed on the members 51 and 59 and are so shaped and situated and of such dimensions as to extend between the sides of the arms 5t and the planes in which the end races of the rotor so are disposed. The elements $9 are provided for the purpose of minimizing flow of fluid past the arms to into the upper portion of "the space 59. Obviously fluid entering the motor G through the inlet 5i and leaving the motor G through the outlet 52 will engage the cups or to produce counter-clockwise rotation of the motor 59 as viewed in Fig. 4. The rotor shaft @321 may be connected through a conventional fiexiblespeedometer drive shaft $9 to a conventional speedometer "it as indicated in Hg. 1.

munication with the inlet passage 6! and the outlet passage 52 is placed in communication with the conduit 39 of Figs. 1 and 2.

flh-e reversing and parking brake valve D includes a casing iii of which the .too and bottom walls lid and lib are removable and are normally held in place by means such as the can screws lie. The interior s ace of the casing H is cylindrical in shape. Within the interior of the casing ii and immediately ad acent the wall We is a dish i2 having the periphery thereofv annularly grooved and provided with an annular sealing element i241 provided in the groove. A disk 93 is provided within the casing ii in somewhat spaced relation with the wall lib so as to provide an auxiliary chamber it between the The conduit 9'! shown in Fig. l and indicated in Fig. 2 is, of course, placed in com inwardly of the sealing elements 89. The disk 13 is provided with apertures 82 therethrough in registration with the recesses 19a so as to place the recesses 19a in communication with each other through the auxiliary chamber M. The disks l2 and i3 and the vanes I9 are adapted for rotation within the casing II as a unit.

For imparting rotation to the rotatable parts a I of a nut 35 applied to a screw-threaded free end portion of the operating element 83. A washer it; is interposed between the nut 85 and the lever 99. Sealing means is provided to prevent leakage of fluid through the joint between the operating element 93 and the bossed portion 1 lb.

This sealing means consists of a flanged washer 8? having the flange portion thereof disposed against the operating element 83 and having a contract element for maintaining the flange portion in firm engagement with the element 83. The sealingelement a1 is disposed within a recess on'the inner side of the bossed portion Nb and is secured'therein by an externally screwthreaded ringed, which is engaged with internal screw-threads formed in the recesses. The ports 15 and l? of the above described valve are connected respectively to the conduit 96 and the automatic valve C. The ports 45 and it are connected to the motor conduits 82 and $3. With the vanes 79 positioned as shown in We. 6 fluid from the pump B may pass throu h the ports Ti and it to the motor conduit 32. and fluid returning from the motors throu h the c nduit 35 may passv through the ports id and it into the conduit 86; If the vane i9 is ro tated through an angie of 98, fluid from the pump B may pass through ports 5? and is into motor conduit 33, and hold returning fr m the the direction of flow of fluid through the motor which is attached to the conduit SI.

the other of the above mentioned positions thereof. If the vane I9 is disposed in an intermediate position on theoommon axis of the ports I5 and I1 flow of fluid in the conduits 32 and 33 will .be blocked. Also fluid will be bypassed from the pump B through the port II, the recess 19a aligned therewith, the auxiliary chamber I4, the remaining one of the recesses 19a, and the port I5 into the conduit 36 wherefrom the fluid may return to the inlet of the pump B. Also the vane I9 may, if desired, be placed in'a second intermediate position 90 from the above mentioned intermediate position and disposed along the common axis of the ports I6 and I8. In this case fluid from one of the motor conduits will be bypassed directly to the other one of the motor conduits 32 and 33,

thus providing free circulation of fluid through the motor as might be required in cases where the vehicle is moved by means other than its own power plant. Also with the vane 'I9 in the last mentioned intermediate position the path for fluid from the pump B through the valve D will be blocked.

Figs. 8, 9 and 10 illustrate the automatic excess pressure relief and free-wheeling valve C. The valve C includes a casing comprising a vertically disposed tubular element 99 joined to and in communication with the medial portion of the lower side of a second tubular element 9|. The respective ends of the tubular element 9| are each provided with an apertured and internally screw-threaded flange 9Ia for purposes of connection to other portions of the system. The respective ends of the element 9| also constitute ports 92 and 93 which are respectively connected to the conduit 39 and to the port 11 of the reversing valve D. The lower end of the vertical tubular element 99 is closed by a closure cap 94 which is screw-threadedly secured therein. Somewhat above the lower limit of the vertical tubular element 99 a third port 95 is provided, this port 95 being defined by a tubular member 96 attached to and in communication with the interiorof the lower portion of the-vertical tubular element 99. The outer end of the. tubular member 96 is provided with an apertured internally screw-threaded flange 99a An internally projecting annular flange 91 is formed in the interior of the tubular element 99 a moderate distance above the port 95. The flange 91 constitutes a centrally apertured partition between the lower and upperportions of the interior of the vertical tubular element 99. Below the apertured partition 91 there is provided a ring-like element 99 of somewhat larger diameter than the aperture 91a of the partition 91. The ring element 99 has an inwardly projecting annular flange 98:: formed thereon. A helical compression spring 99 is placed under pressure between the flange 98a and a series of disks I99 carried by the upper side of the closure cap 94. A ball IN is placed above the ring member 98 to cooperate with the flange 99a thereof in forming a check valve. With the aperture 98b defined by the free edge of the flange 98a closed by the ball IN. the flange 99a and the ball I9I co-operate with the flange 91 to form a second check valve. To prevent movement of the ball I.9I' beyond a reasonable distance above'the flange 99 a pin I92 is secured to and disposed diametrically of the upper portion of the tubular element 99 as shown. To-maintain the ring element 99 in centered relation with the tubular element 99 vertically extending guide ribs 980 are provided on the exterior periphery thereof. Adjustment of the tension of the spring 99 may be effected by increasing or decreasing the number of disks I99. For purposes of bleeding air from the interior of the valve C the upper side of the horizontal tubular element 9| is provided with a screw-threaded and headed plug I93 screwed into a suitable internally screw-threaded apertured portion of the tubular element 9|. In operation of the device an excess pressure existing in the upper portion of the tubular element 99 will force the ball MI and the flange 98a downwardly against thepressure of the spring 99 to separate the flange 98a from the flange 91 and thus allow fluid to flow past the flanges 91 and 98a downwardly and out through the port 95 into the bypass conduit 3|; The spring 99 is suflicientl-y strong to prevent bypassing of fluid under conditions where normal operating pressures exist in the upper portion of the valve C. The ball I9I will rise from its seat responsive to any fluid pressure below the ball I 9| in excess of the fluid pressure above the ball I9I. cases where the vehicle is in motion and the pump B is adjusted to change its output to a reduced amount or to zero the motors E would be driven by the wheels of the vehicle and would begin to function as pumps. If flow of fluid responsive to pumping action of the motors E should be blocked the speed of the vehicle would be slackened rapidly or even abruptly. However, the ball I9I will be lifted to permit circulation therepast of fluid pumped by the motors E.- With freedom for circulation of fluid pumped by the motors E a free-wheeling eflect is obtained and the vehicle will not be slackened in speed rapidly or abruptly due to reduction or stoppage of the output of the pump B.

Figs. 11 to 14 inclusive illustrate means for restricting and, if desired, stopping flow of fluid resulting from pumping action of the motors E when the pump B is shut down. The valve F of Figs, 11 to 14'constitutes the braking means of my hydraulic propulsion and control system. The valve F includes a casing I94 having an interior space I95. The casing I94 is provided at respective opposite sides thereof with outwardly projecting tubular extensions I96 and 7 I91 disposed in co-axial relation to each other and respectively defining a fluid inlet passage I 96a and a fluid outlet passage I 91a. The inlet and outlet passages Mia and I9'Ia are respecprovided respectively with apertured flanges I952) and I91b. An elongated element I 99 is contained within the interior space I95 of the easing I 94 and at its respective ends extends into the inlet passage I96a and the outlet passage in co-axial relation therewith. To maintain the element I99 in said co-axial relation guide elements are provided at each end of the element I99 to work in the interiors of the tubular projections. I 99 and I91. The guide elements each consist of, a flat ring I99 having therewithin a spider I99a secured at its free ends to the ring I99. Recesses I99b are formed in the legs of the spider element I99a and the portions of the ring I99 registering with the legs of the spider. The recesses I99b are radially disposed and open outdrical element wardly and each is provided with a plunger IIO therein for engagement with the interior periphery of the corresponding tubular projection I06 or I01. Helical compression springs III are disposed between, the innersides of the plungers H and the bottoms of the recesses I09b. The

-annular corner II2 consisting of the part of the casing I04 defining theinner end of the inlet passage I06a is utilized as a valve seat and suitable valve means for co-operating with the seat II2 is provided. The portion of the elongatedelement I08 adjacent the valve seat. H2 is enlarged to provide a conical valve element I080. and a cylin- I08b disposed immediately inwardly of the valve element "Mia. The valve element I08a is tapered toward the inlet passage I 06a. It should be apparent that the flow of fluid through the inlet passage I06a will be diminished as the valve element I08a approaches v the seat I I2, and will be stopped when the valve element I08a has become engaged with the valve seat H2. 7 v Means is provided for projecting the valve element IOBa toward the valve seat H2. inwardly of the cylindrical enlarged portion 10b of the elongated element I08 the element I08 is widened as indicated in Figs. 11, 12, and 13 to form a flat portion I080 adjoining the cylindrical enlarged portion I08b. The upper wall I04a of the casing I00 is of increased thickness and is centrally apertured. A shaft I I3 is journalled in the centrally apertured wall- IMaof the casing I00 and. carriesonits inner end immediately adjacent the wall I0ta a located pin II5. A ball bearing H6 is provided,

the inner race IIBa of which is mounted on the pin I I5. and the outer race I I6b' of which bears in a portion of its periphery against the inner side of the cylindrical portion I00b of the elongated element I08 therein. The dimensions of the parts associated with and adjoining-the ball bearing IIS are such that the races II6a and II6b are confined between the disk H0 and the upper surface of the widened portion I060 of the elongated element I00. The shaft H3, when rotated to shift the eccentrically carried ball bearing II6 to the right, serves as an operating means for projecting the valve element I00a to .the right so that the same will approach or engage the valve seat H2. When the shaft H2 is rotated so that the ball bearing I It moves to the left, pressure of fluid in the inlet passage 106a will act upon the valve element I06a to'cause the same to follow the ball bearing 5 I6 and maintain the cylindrical enlargement I001) in engagement with the outer race II6b of the ball bearing H6. To prevent leakage. of fluid from the interior of the valve past the shaft H3 a flanged sealing ring In is placed in an annular recess H8 in the outer portion of the wall Ma. .The sealing ring ill encircles the shaft H3 and is maintained in firm engagement therewith by means of an annular contractile element H0. The sealing ring II! is secured in the recess see by means of an externally screw-threaded collar E screwed into internal screw-threads formed in the outer portion of the recess H0. Means for rotating the shaft I I3 is provided. outwardly of the wall I041; the shaft I I3 is provided with a reduced dimension portion H311 on which an operating lever MI is mounted. The operating lever MI is secured to the shaft M3 by means of a nut I22 screwed on to screw-threads formed on the washer I23 is interposed between the nut I22 and the outer side of the operating lever I2 I.

The wheel motors E may be of any type wherein the motor is reversible and rotates in directions corresponding to the direction of flow of fluid therethrough, wherein the construction is such that the motors can function as a pump and wherein the construction is such that substantially a fixed amount of fluid will flow through the motor per revolution thereof.

The pump B as previously mentioned may be of any type which is variable in regard to the output as expressed in the volume of fluid displaced thereby per revolution, and which is controllable to vary the output from a maximumdown to zero output. In Fig. 1 I have represented the control element for varying the output of the pump B by a longitudinally movable rod I24. For 0p-' crating the rod I24 I prefer to employ any suitable type of pneumatic means for producing mechanical movement responsive to application of vacuum thereto. In Fig. l I have indicated such means by the numeral I25. Suitable valve means is, of course, required for controlling application of vacuum to the vacuum actuated device I25. Valve means for this purpose is identified in Figs. 1 and 15 by the numeral I26. The vacuum control valve I26 should be constructed to afford both the function of shutting ofi the supply of vacuum to the pump adjusting device I25 and also through suitable means operating responsive to movement ofthe pump adjusting rod I24 to carry on the function of controlling communication of vacuum with the device I25 in such manner as to limit the degree of pump output. The device I26 is provided with a fitting I20a to which a conduit such as the conduit I 26b leadingtoa source of vacuum is connected. The valve device I26 includes shut-off means for shutting oflf the supply of vacuum to the device I25 and opening the interior of the device I25 to the atmosphere. A control element I260 is provided for control of the vacuum shut-off means. The device I26 includes means operated by a rod I26d for respectively communicating vacuum with the device I25 and venting the device" I25 to the atmosphere. The rod I26d carries an arm' I26e to which the casing of an armored pull wire control element I26,f is anchored. A guide rod I26g is provided on the device I26 and at its outer end projects through an aperture in an arm I24a carried by the pump adjusting rod I 24. An element I26h is carried on the rod I26g in longitudinal relation thereto. The element I26h is adapted to be engaged by the arm I24a to cause movement of the rod I26d. The control wire I267 of the control means I26) v is connected at its free end to the element I25h whereby the control means I261 may be operated to adjust the position of the element I26h on the rod I26g and thus determine the degree of pump output at, which the arms I20a will engage th element I251 to move the rod I26d and thus control the degree of vacuum in the device I25 so as toprevent further increase in the output of the pump B.

The engine 26 includes an intake manifold 20a of conventional type upon which is mounted a carburetor I21 having a throttle operating lever I2Ia. For control of the throttle lever I2Ia I provide a vacuum actuated device H shown in Figs. 15 and 16. The device H includes an apertured mounting element I28 which may be secured to any stop supporting means such as outermost portion 30 of the shaft H3. A .a part of the engine 20. Carried by th ttubular element I29a with the left-hand end of the space I29c. Theright-hand end of the cylinder element I291) is provided with an apertured end wall I29d. The left-hand end of the cylinder element I29b is provided with a screwthreaded elongated plug I33 screw-threadedly engaged in the left-hand end of the cylinder element I281). The plug I33 is provided with a head I33a by means of which the plug I33 may be adjustively screwed inwardly and outwardly of the cylinder element I29b. A look nut I34 is provided on the plug I 33 for locking the same in any desired adjusted position thereof. In its medial and inner end portions the plug I33 is provided with a cylindrical inwardly opening recess I33b. A piston I35 is placed in the space between the plug I33 and the end wall I29d. At its left-hand end the piston is provided with a cylindrical leftwardly opening recess I35a. A helical compression spring I36 extends between the plug I33 and the piston I35 and is seated at its respective ends in the respective recesses I33!) and I35l1; The piston I35 carries thereon a reduced diameter portion I35b extending to the right through the aperture of the apertured end wall I29d and constituting a piston rod. The outer-end of the piston rod [35b is connected to the throttle arm I21a by a link I31 which is pivotally connected at its respective ends to the piston rod I35b and the throttle arm I210. A flexible cup I38 is provided as shown in Fig. 16 to serve as a dust shield for preventing entrance of dust into the portion of the piston rod I35b which moves in the apertured end wall I29d. The above described throttle control device shown in Fig. 16 is so arranged that the'same will act when the vacuum in the intake manifold 28a decreases and increases to respectively increase and decrease the degree of throttle opening of the throttle included in the carburetor I21 and controlled by the throttle arm I21a. The throttle control device H shown in Fig. 16 working in co-operation with the vacuum control valve I26 is adapted more particularly for use in connection with my system when the motors E will normally be operated continuously at a fixed speed. Assuming a normal degree of vacuum in the manifold 28a and the normal load on the motors E the throttle arm I21a will be disposed at a certain position. If the load on the motors E increases there will be a tendency to increase the torque. imposed on the engine 28 with the result that the engine will slow down somewhat and the degree of vacuum in the manifold 28a will be reduced. Reduction of vacuum in the manifold 28a will cause the device H to increase the degree of throttle opening and simultaneously will operate the device I25 to decrease the volume of liquid displaced by the pump 13 per revolution. This will in effect increase the ratio between the revolutions of the engine 28 and the revolutions of the wheel motors E. Reduction in torque occasioned by the increase in ratio and the increase in throttle opening caused by reduction in manifold vacuum will cause the engine 28 to speed up so that the speed of rotation of the motors E will remain substantially the same as before the increase in load and the torque developed by the motors E will be increased. When the load is again decreased the vacuum in the manifold 28a will increase to effect reduction in throttle opening by means of the device H and to increase the volume of fluid displaced per revolution by the pump B through action of the device I25. Thus the ratio between the revolutions of the engine 28 and the revolutions of the motors E and also the degree of throttle opening will return to normal when the load on the motors E has returned to normal.

Control means to be operated by the driver of a vehicle in which my system is included are provided as shown in Figs. 17 and 18. In Fig. 17 the numerals I39 and I40 designate the respective floor board and toe board ordinarily found forward of the driver's seat in an automotive vehicle. A foot operated control element I is provided in the position occupied by the clutch pedal. The control element I may be in the form of a plate connected at its lower end to the toe board I40 by means of a hinge or pivot device I4Ia. A curved rod I42 extends through an aperture a in the toe board I40 and at its upper end is pivotally connected to the upper end of the control element I. A helical spring I43 is placed on the rod I42 between the toe board I40 and the plate I so as to normally hold the plate I in upwardly and rearwardly deflected position. The lower end of the rod I42 is pivotally connected to one arm I44a of a bell crank I44. The bell crank I44 is pivotally mounted on a bracket I45 secured to the lower side of the toe board I40. The remaining arm I44b of the bell crank I 44 is connected through a link I48 to the forward end of a rod I41, this rod I41 being forwardly and rearwardly slidable in a tubular guide element I48 which is secured to the lower side of the floor board I39. The control element I281 is anchored in the rear end to the tubular guide I48. The longitudinally slidable wire I267 of the control element I26! is connected to the slidable rod I41. When the control element or pedal MI is pressed downwardly the wire I247 will be pushed toward the vacuum control device I26 and will push the element I23h toward the pump B so as to limit the degree to which the volume of fluid displaced by the pump B per revolution may be increased. Pressing the pedal I all the way down will cause-the output of the pump B to be reduced to zero, thus affording an action in my system corresponding to disengagement of the clutch of a conventional motor vehicle, Referring to Fig. 18 a control rod I43 extending longitudinally of the vehicle is shown. The forward end of the control rod I49 may be connected to a pedal similar to the usual motor vehicle brake pedal and similarly situated. Th connection of the rod I49 to a brake pedal should, of course, be such that movement of the rod I48 responsive to depressing the brake pedal will be toward the left as viewed in Fig. 18. The rear end of the rod I49 which is the right-hand end as viewed in Fig. 18 is connected to the operating lever I2I of the brake valve F previously described. An apertured element I50 is mounted on the arm I2I and the rod I49 is extended through the aperture thereof. Forwardly of the element I50 a collar I BI is secured on the rod I49. The rear end of the rod I49 is screwthreaded and carries thereon a wing nut I52. A helical compression spring I53'is placed on the rod I49 between the wing nut I52 and the apertured element I50. Pressure applied to the brake pedal is transmitted through the wing nut I52 and the spring I53 to the element I50 so as to move the arm I2I in such direction as to cause the valve element IIl8a of the brake valve to move toward the valve seat II2 of the brake valve F.

Release of the brake pedal which, of course,

should be provided with the usual pedal return spring will cause the collar II to return the brake valve operating lever I2I to the normal position thereof. The valve of the device I26 which disconnects the device I from the source of vacuum and opens the device I25 to the atmosphere is also actuated to carry out its function responsive to the depression of the brake pedal, that is, forward movement of the rod I49. The armored pull wire control element I260 controlling the valve mentioned is anchored at the end thereof opposite the device I26 in the rear end ofa tubular element I54 which is supported from the frame I25 of the vehicle by means of a bracket I55. Within the tubular element I55 is a rod I56 which is slidable longitudinally of the tubular element I55. The pull wire I 26k of the control element I260 is connected to the slidable The brake operating rod I49 carries braking action is transmitted through the arm I51, the spring I55, the collar I58, and the rod I55 to the pull wire I26k to cause shutting ofi of vacuum from the device I25 and connection of the device I25 to the atmosphere. This will cause reduction of the output of the pump B to zero.

In motor vehicles called upon for operation at variable speeds a means of operating the throttle.

arm I21a somewhat diiferent from the means H shown in Fig. 15 is provided.- The different means is shown in Fig. 19. A rod I65 is provided and may be connected at its forward end to a foot throttle or accelerator pedal of conventional design and situated in the manner of the usual motor vehicle accelerator pedal. The rod IE5 is so associated with the accelerator pedal that depressing of the pedal will move the rod I68 to the left as viewed in Fig. 19. The rear end of the rod I68 is pivotally connected to one arm 15111 of a bell crank ISI which is mounted for swinging movement'about a fixed pivot pin I52. Thereaxle members I12 are so shaped as to extend maining arm I5Ib of the'bell crank I5I has pivv otally connected thereto a rod I53. A vacuum I61 so as to be restrained from longitudinal movement relative ther to. A pistonrod I55 is proyided on the piston I65 and the free end of the rod I69 is pivotally connected to the throttle operating arm I21a of the carburetor I21. The device J is not mounted in a fixed position but is supported from the rods I53 and 159. A connection element. I18 communicating with the left-= hand portion of the space within the cylinder element I64 and adapted for connection 'of a suitable conduit thereto is provided. A flexible conduit or tube IN .is provided to connect the connection element I10 to the intake manifold 28a so that vacuum produced in the intake manifold 28a will be in communication with the interior of the device J. In use of the device J the degree of throttle opening is determined largely bythe position of the accelerator pedal and with the accelerator pedal in a given position the degree of throttle opening will be varied to a relatively small extent by the vacuum actuated device J. This results in partial control of the degree of throttle opening to compensate for variation in the load on the motors E. The vacuum control valve I26 associated with the pump output control device I25 is arranged in the same manner when the device J is used as it would be arranged when the device H is used and accordingly provides for the same control of the ratio between the revolutions of the engine 28 and the revolutions of the motors E.

The lever for operating the reversing and parking brak valve may be connected through any suitable mechanical means of bnventional with my hydraulic device to produce a highly desirable unitary result. At each end of the frame 25 I provide a pair of axles I12 each of which is pivotally connected at one end thereof to a member I13 mounted on one side of the frame 25 and extends at its free end portion I12a beyond the opposite side of th frame 25. The

from the member I13 downwardly and toward the center of the frame and then at a gradual incline to the free end H241. The medial portions of the members 112 are so bent as to enable the same to cross with clearance therebetween and the free end portions I121; of the respective axles I12 are aligned transversely of the frame 25. Radius rods I15 are connected to the free end portions 112a of the respective axles I12 by means of bolts I15 extending through the axle I12 and through a pair of spaced projections IIda. provided on the end of the radius rod I15 and disposed respectively above and below the axle I12. From the axle I12 'the' radius rods I14 extend a substantial distance toward the middle portion of the frame 25 and are at their free ends provided with ball and socket connecting means I18 connecting the radius rods I15 to the frame 25. The free ends 112a of the axles I12 are connected to the frame 25 through resilient means so that the axles I12 may be deflected vertically upwardly and downwardly relative to the frame 25. Cantilever type leaf springs I11 are anchored at their normally fixed ends to the extreme ends of the fram 25 by means of suitable clamps I18. The free ends of the springs I11 are connected to the radius rods I14 closely adjacent the axles I12 by meansof shackles I15 whichmay be of substantially conventional construction. Snubbers or shock absorbers I58 which may be of convenportions of the motors E. The steering knuckle assemblies I8I carry steering arms I8Ib which are connected through steering links I82 to the rear arm I83a of a double arm steering lever I83. The links I82 are, of course, pivotally connected at their ends to the steering arms I8") and the steering lever I83. The forward arm I83b of the steering lever I83 is connected through a link I84 to the swin'gable steering element I85a of a conventional steering head I85 which is connected through a steering shaft I86 to a conventional steering wheel I81. On the rear pair of axle members I12 steering knuckles are not necessary and hence the plates I8Ia upon which the wheel motors Eiare mounted may b rigidly mounted directly on the free end portions "211 of the rear axle members I12. The construction just described provides knee action or independent springing of each and every one of four wheels of a vehicle, and propulsion and braking action of the wheels 26 is provided through my hydraulic means which require connections between apparatus on the frame 25 and the wheel motor units E of a flexible nature. The use of flexible conduits in place of brake rods and axle shafts makes possible the wheel suspension construction described.

In my hydraulic propulsion system having four hydraulic wheel driving motors differentialaction when the vehicle is following other than a depressed and th 'pedal I may be permitted to rise a short distance from its fully depressed position. Through operation of the vacuum control valve I26 and the pump adjusting device I25 the pump B will then be adjusted for a relatively low displacement of fluid per revolution, and hence the ratio between the engine revolutions and the revolutions of the wheel motors E will be large and the transmission of power from the engine to the wheel motors will be under conditions corresponding to use of the low gear in the conventional motor vehicle transmission. As the pedal MI is subsequently allowed to rise farther and farther the gear ratio effect of the hydraulic transmission system will be gradually varied by extremely small increments toward a condition corresponding to that existing in a conventional motor vehicle when the transmission thereof is in .high gear. The change in transmission ratio just transmission ratio between the engine andthe straight path is inherently provided since the motors have individual parallel paths therethrough betweenwhich the total output of the pump B may be divided either equally or unequally as conditions require. The fluid used in my system is preferably of such natur as to have lubricating ability whereby the working parts of the pump. wheel drive motors, speedometer drive motor and other devices in the system are lubricated without the need for any equipment specifically for. providing lubrication. Drain plugs and air bleeding plugs may be provided at various points in the system as desired in accordance with usual practice in hydraulically operated equipment. In use of the system the engine 28 may be started by ISO wheel motor and the device J will act to'produce a moderat increase in throttle opening. Operation of the device J may, of course, be augmented by increased pressure on the accelerator pedal. When it is desired to permit th vehicle to coast the accelerator pedal may be released to return to the position thereof corresponding to closure of the throttle. The engine 28 will be reduced in speed down to an idling speed and the output of the pump B will be greatly diminished. The vehicle will continue to coast because of the free-wheeling effect permitted by raising of the ball IIII in the excess pressure release and freewheeling valve C. If desired the pedal Ill may be depressed to close on the pump B. If it is desired to slow down th vehicle rapidly or stop the vehicle the brake pedal may be operated to restrict or stop flow of fluid through the wheel motors E. When the vehicle has been stopped the reversing valve-D may be placed in parking position in order to permit idling of the engine 28.

It is to be pointed out that the motor conduits 32 and 33 may, if desired, have fluid motors other I than the motors E connected thereto. Such mostarting equipment identically like that found in conventional motor vehicles. During the process of starting the engine either the brake pedal or the pedal I may be depressed to adjust the pump B for zero output, or the control element for the reversing and parking brake valve D may be placed in parking position so as to bypass fluid from the outlet back to the inlet of the pump B. Until the engine has started and vacuum has been built up in the intake manifold the pump adjusting devic I25 will function to maintain the pump B adjusted for zero output.

After the engine has been started and it is de- I sired to place the vehicle in motion the reversing valve D will ordinarily be in parking position and preferably the pedal Ill will be in depressed position, The reversing valve may then be shifted to either forward or reverse position if desired. The accelerator .pedal should ordinarily be slightly tors may be stationary motors, as for example, motors to operate a winch carried by the vehicle. In such case it would, of course, be desirable to provide stop valves in the'fiuid path to thestationary motor and provide other valves for shutting off flow of fluid to the wheel motors E.

Where a trailer is used with the vehicle, wheel motors similar to those used in the vehicle itself maybe provided in connection with the wheels to the trailer. Flexible conduits may be extended from the motor conduits 32 and 33 to the trailer, and the wheel motors associated with the trailer wheels. In such case the motor 28 will apply tractive effort not only to the wheels of the vehicle itself but also to the wheels of the trailer. Furthermore, use of the brake valve of the vehicle will cause braking action not only on the wheels of the vehicle but also on the wheels of the trailer. My system is also well adapted for use in transmitting power from an engine or any ,other source of rotary mechanical power to fluid motors in equipment of a different nature than vehicles.

It is apparent that I have invented a novel, effecitve and efllcient hydraulically operated system for propulsion, braking and control of motor vehicles.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of my invention.

What is claimed is: l

1. In a hydraulic vehicle propulsion system including a power driven fluid pump having an outlet conduit running to the inlet of a fluid motor equipped with an outlet conduit in which a braking valve is interposed, a fluid reservoir drop of the liquid level in said'reservoir will expose said pump inlet connection and halt the supply or power to said fluid motor, but said bypass connection will remain covered and permit functioning of said brake valve.

2. A hydraulic vehicle propulsion system including, a reversible, wheel-driving hydraulic motor having a pair of fluid ports one or the other of which functions as a fluid inlet port dependent upon the direction of rotation desired reservoir, a conduit connecting the lower portion of said reservoir to the inlet of said pump, an

auxiliary fluid motor connected in series with said return conduit to be operated by fluid flowing therethrough and positioned between said valve and said reservoir, and rotational speed indicating means driven by said auxiliary motor -to indicate approximately the rate of fluid flow through said return conduit.

HERBERT J NATHAN. 

